Android: If you're stuck in an office where you have to sit with your back to a walkway or the entrance to your cubicle, you know how startling it can be when you're listening to music and someone walks up behind you and taps you on the shoulder. Around Sound for Android makes sure that never happens again—the app uses the microphone on your headset or your phone as an extended ear, and if a loud noise is detected, the app will pause your music so you can pay attention.

The app allows you to set the trigger volume manually so you don't find your music pausing all the time for false positives, like construction noise outside your window or someone walking past your desk on their phone. You can also tell the app to play back the sound that triggered it, so you know whether it's something you should pay attention to. The developer said that he wrote the app so he could listen to music while he worked but never miss his dogs barking so he could check out what upset them—you can use the app for the same purpose, or for those times when someone walks up behind you and tries to get your attention without startling you.

Before you give the app a shot, keep in mind that it works seamlessly with most stock music players and a few others, including DoubleTwist, Winamp, and our favorite, PowerAmp. The app is completely free and available now at Google Play for devices running Android 2.2 or higher. There's also a $0.99 pro version which adds a few features and supports the developer.